This is an application from the Division of Urology of the University of Pennsylvania Health System (UPHS) to participate as a clinical site for the Interstitial Cystitis Clinical Research Network (ICCRN). The UPHS clinical site encompasses the core group of highly talented and experienced investigators who worked as a part of the Interstitial Cystitis Data Base Study and in the Interstitial Cystitis Clinical Trials Group (ICCTG), currently in its 5th year. The Div of Urology of the UPHS and the Univ of Pennsylvania has demonstrated their support and commitment to research on IC by actively participating in ICCTG #1 and #2. The Division of Urology of the UPHS Center, supports the broad research goals of the NIDDK with regard to interstitial cystitis (IC) and related disorders, through the following specific aims: Aim 1: To maintain our IC clinical network pertaining to all aspects of patient care, including recruiting and retaining patients with an appropriate age, race, and gender representation; providing high quality care; monitoring and ensuring safety; and coaching and encouraging subjects to be compliant with study protocols. Aim 2: To collaborate and provide scientific expertise on IC in all phases of the clinical trials and associated basic science or clinical additions to the core studies to aid in the discovery of new ways to determine the etiology, most efficient diagnosis, and best treatments of IC. Aim 3: To conduct objective, controlled, scientifically validated studies in order to determine the overall utility and efficacy of a variety of novel therapies for IC. A Central component is to continuously review and refine entry criteria as well as outcome parameters as additional scientific evidence becomes available. Aim 4: To work together as part of the Urological Chronic Pelvic Pain Syndromes Collaborative Group (UCPPSCG) with the following goals: (1) to shorten the period of protocol development, (2) to collect common information to permit comparisons of the clinical characteristics of these two conditions, (3) to facilitate decisions on treatments to be evaluated, and (4) to increase the rate of accrual of study participants. Aim 5: To develop a suitable clinical definition of IC, a clinically and scientifically based assessment of where the disease falls in the spectrum of chronic pelvic pain, pelvic floor dysfunction, and prostatitis.